基于msp430f5529的避障小车程序

以下是基于 MSP430F5529 的避障小车程序的一个简单实现：

#include <msp430.h>

#define LEFT_MOTOR BIT0
#define RIGHT_MOTOR BIT1
#define TRIG BIT2
#define ECHO BIT3
#define LED BIT6

#define TRIGGER_PULSE_WIDTH 10 // 10 us
#define SPEED 60 // motor speed (0-100)

volatile unsigned int distance = 0;
volatile unsigned int is_measuring_distance = 0;

void initGPIO() {
    // Motor pins as output
    P1DIR |= LEFT_MOTOR + RIGHT_MOTOR;
    P1OUT &= ~(LEFT_MOTOR + RIGHT_MOTOR);
    // Trigger pin as output
    P3DIR |= TRIG;
    // Echo pin as input
    P3DIR &= ~ECHO;
    // Led pin as output
    P1DIR |= LED;
    P1OUT &= ~LED;
}

void initTimer() {
    TA0CTL = TASSEL_2 + MC_0 + ID_0;
    TA0CCR0 = 65535;
    TA0CCTL1 = OUTMOD_7;
    TA0CCR1 = 0;
    TA0CCTL2 = OUTMOD_7;
    TA0CCR2 = 0;
}

void delay_us(unsigned int us) {
    TA0CTL |= TACLR; // clear timer
    TA0CTL = TASSEL_2 + MC_1 + ID_0; // SMCLK, up mode, no division
    TA0CCR0 = us - 1; // set timer period
    while(TA0CTL & TAIFG == 0) {} // wait for timer to complete
    TA0CTL &= ~TAIFG; // clear interrupt flag
}

void triggerDistanceMeasurement() {
    P3OUT |= TRIG; // send a pulse
    delay_us(TRIGGER_PULSE_WIDTH);
    P3OUT &= ~TRIG;
}

void startMeasuringDistance() {
    is_measuring_distance = 1;
    triggerDistanceMeasurement();
}

void stopMeasuringDistance() {
    is_measuring_distance = 0;
}

unsigned int measureDistance() {
    startMeasuringDistance();
    while(is_measuring_distance) {}
    return distance;
}

void processDistance() {
    if(P3IN & ECHO) { // rising edge
        TA0CTL |= TACLR; // clear timer
        TA0CTL = TASSEL_2 + MC_2 + ID_0; // SMCLK, continuous mode, no division
    } else { // falling edge
        distance = TA0R / 58; // calculate distance in cm
        TA0CTL &= ~MC_3; // stop timer
        stopMeasuringDistance();
    }
}

void moveForward() {
    P1OUT |= LEFT_MOTOR;
    P1OUT &= ~RIGHT_MOTOR;
    TA0CCR1 = SPEED * 10;
    TA0CCR2 = SPEED * 10;
}

void moveBackward() {
    P1OUT &= ~LEFT_MOTOR;
    P1OUT |= RIGHT_MOTOR;
    TA0CCR1 = SPEED * 10;
    TA0CCR2 = SPEED * 10;
}

void turnLeft() {
    P1OUT &= ~(LEFT_MOTOR + RIGHT_MOTOR);
    TA0CCR1 = SPEED * 10;
    TA0CCR2 = 0;
}

void turnRight() {
    P1OUT &= ~(LEFT_MOTOR + RIGHT_MOTOR);
    TA0CCR1 = 0;
    TA0CCR2 = SPEED * 10;
}

void stopMoving() {
    P1OUT &= ~(LEFT_MOTOR + RIGHT_MOTOR);
    TA0CCR1 = 0;
    TA0CCR2 = 0;
}

int main(void) {
    WDTCTL = WDTPW + WDTHOLD; // disable watchdog timer
    initGPIO();
    initTimer();
    __enable_interrupt(); // enable interrupts globally

    while(1) {
        unsigned int d = measureDistance();
        if(d < 10) { // obstacle detected, stop and turn
            stopMoving();
            P1OUT |= LED;
            delay_us(500000); // wait for 0.5s
            P1OUT &= ~LED;
            if((rand() % 2) == 0) {
                turnLeft();
                delay_us(1000000); // wait for 1s
            } else {
                turnRight();
                delay_us(1000000); // wait for 1s
            }
            moveForward();
        } else { // move forward
            moveForward();
        }
    }
}

在上面的代码中，我们使用了 MSP430F5529 的定时器和GPIO来控制小车的运动和测量距离。程序中通过超声波模块测量距离，并根据距离的大小来控制小车的行动。当距离小于10cm时，小车会停止并向左或向右转动，然后再前进。否则，小车将一直向前行驶。